Process and system for dewrinkling garments

ABSTRACT

WRINKLES ARE REMOVED FROM PRESTEAMED GARMENTS BY A BRIEF HEAT TREATMENT AT A TMEPRATURE ABOVE THE SOFTENING TEMPERATURE OF THE CONTAINED THERMOPLASTIC RESIN FOR A TIME LESS THAN REQUIRED TO SUBSTANTIALLY DEGRADE THE RESIN, AND IN THE PRESENCE OF HIGH VELOCITY, E.G., 1400-2000 FEET PER MINUTE, DOWNWARDLY DIRECTED AIR. THE STEAMING AND HEAT TREATMENT TYPICALLY CAN BE CARRIED OUT IN EQUIPMENT SUCH AS DISCLOSED IN U.S. PAT. NO. 2,911,729. THE DEWRINKLING TECHNIQUE IS ALSO USEFUL IN THE PROCESS OF MANUFACTURING &#34;PERMANENT PRESS&#34; GARMENTS WITH THERMOSETTING RESIN IN WHICH THE THERMOETTING RESIN IS APPLIED TO THE FABRIC EITHER PRIOR TO OR AFTER BEING MADE INTO A GARMENT BUT IS LEFT IN AN UNCURED CONDITION UNTIL DEWRINKLED AS ABOVE. AFTER DEWRINKLING THE GARMENTS ARE TREATED AT A SUFFICIENT TEMPERATURE AND TIME TO SET THE RESINS. LAUNDERED GARMENTS ARE DEWRINKLED BY FIRST PRECONDITIONING THEM. THE PRECONDITIONING TYPICALLY INCLUDES LAUNDERING AT ABOUT 110 TO 190*F., THEN GRADUALLY COOLING ABOUT SIX MINUTES, THEN SPIN DRYING ABOUT THREE TO FIVE MINUTES. THE GARMENTS ARE THEN DEWRINKLED BY THE ABOVE PROCESS, FOR A SLIGHTLY LONGER PERIOD DUE TO THE PRESENCE OF MOSISTURE IN THE GARMENTS, OR MAY BE PREDRIED PRIOR TO BEING TREATED BY THE ABOVE DEWRINKLING PROCESS BY DRYING AT ABOUT 130*F. FOR SIX MINUTES AND THEN GRADUALLY COOLING TO ABOUT ROOM TEMPERATURE.

April 27 l971 J. w. DEKoEKKor-:R 3,576,661

PROCESS AND SYSTEM FOR DEWRLNKLING GARMENTS Filed Aug. 11. 1969 United States Patent PROCESS AND SYSTEM FOR DEWRINKLING GARMENTS John W. Dekoekkoek, Seattle, Wash., assignor to Western Automation Corporation, Seattle, Wash.

Filed Aug. 11,1969, Ser. No. 848,960A

Int. Cl. B08b 7/04; B44d 1/48 U.S. Cl. 117-62 18 Claims ABSTRACT OF THE DISCLOSURE Wrinkles are removed from presteamed garments by a brief heat treatment at a temperature above the softening temperature of the contained thermoplastic resin for a time less than required to substantially degrade the resin, and in the presence of high velocity, e.g., 1400-2000 feet per minute, downwardly directed air. The steaming and heat treatment typically can be carried out in equipment such as disclosed in |U.S. Pat. No. 2,911,729'. The dewrinkling technique is also useful in the process of manufacturing permanent press garments with thermosetting resin in which the thermosetting resin is applied to the fabric either prior to or after being made into a garment but is left in an uncured condition until dewrinkled as above. After dewrinkling the garments are treated at a suflcient temperature and time to set the resins. Laundered garments are dewrinkled by first preconditioning them. The preconditioning typically includes laundering at about 110 to 190 F., then gradually cooling about siX minutes, then spin drying about three to five minutes. The garments are then dewrinkled by the above process, for a slightly longer period due to the presence of moisture in the garments, or may be predried prior to being treated by the above dewrinkling process by drying at about 130 F. for six minutes and then gradually cooling to about room temperature.

BACKGROUND OF TI-DE INVENTION Garments made primarily from fabrics consisting primarily of natural fibers, such as cotton or wool, are dewrinkled either by pressing or treating them in a dewrinkling process. Such dewrinkling process usually employs the steps of steaming the garments and then heating them by an air stream. Such a process is shown, for example, in the U.S. patent to Wood, U.S. Pat. No. 2,911,729.

With the advent of garments made from synthetic fibers of thermoplastic resin, such as nylon, rayon and the like, the dewrinkling process suitable for natural fibers has proved to be unsuccessful. Garments made totally or partially from synthetic bers have a degradation temperature above which the fabric deteriorates if held at that temperature for an extended period of time. Garments made from natural or synthetic (fibers and treated with a thermosetting resin to impart a wrinkleresistant characteristic contain a resin which after curing renders the fabric with a memory tending to restore it to its post-cured shape. Typical processes for forming socalled permanent press garments by impregnation with a urea-formaldehyde resin or the like are disclosed in Warnock et al. U.S. Pat. Nos. 2,974,432 and 3,268,915, for example. All such permanent press garments are difficult to dewrinkle after being in prolonged storage in a wrinkled state or after laundering or other treatment at high temperatures. To overcome this diiculty various new approaches has been used to dewrinkle the thermoplastic and/ or thermoset resin treated garments. Typically of these new techniques are the processes disclosed in Ebert U.'S. Pat. No. 3,304,620 and Wentz U.S. lPat. No.

3,257,739. In these processes, however, a heat treating temperature below the curing temperature of the thermosetting resin or resins or the degradation temperature of the thermoplastic resin liber is always employed. In fact, these processes specically indicate ythat to treat the garment at a temperature higher than these curing or degradation temperatures is not only a disadvantage but is likely to damage the garment. In both of these prior processes, although improved dewrinkling results, the processes are slow and the nal condition of the garment is often unacceptable in the trade.

SUMMARY OF 'I THIE INVENTION A basic feature of this invention is to dewrinkle garments, particularly garments consisting of at least a portion of a thermoplastic synthetic fabric with or without a thermosetting resin to instill dewrinkling qualities. The process includes heat treating the garment for a short time at a temperature above the softening temperature of the contained thermoplastic resin for a time less than that required to substantially degrade the resin. Signidicant to the process is the heat treating of the garments for only a brief period of time, substantially less than the time required to substantially degrade the thermoplastic resin. In the preferred form of the invention, the garments are dirst presteamed to condition the fabric and are heat treated in the presence of a downwardly directed, high velocity stream of air. The results of such a technique are a great improvement in de'wrinkled quality over lower temperature processes, and quickly produce a high quality appearance in the garments.

Another feature of the invention is to utilize the dewrinkling process in the treatment of freshly laundered garments by gradually cooling and substantially drying the garments prior to subjecting them to the above de- Wrinkling process. In one form the substantially dried garments are further dried at about for about six minutes and then gradually cooled to room temperature (i.e. about 70 F.) prior to being processed by the above dewrinkling process, the gradual cooling being desirable to avoid so-called shock wrinkles being formed in the garment.

Still another feature is the use of the above dewrinkling process in the manufacutre of permanent press garments. 'Basically in a permanent press garment a thermosetting resin is applied to the fabric either before or after the garment is fabricated but the thermosetting resin is not cured or set until after the garment is made. Prior to curing the resin, but after making the garment, the above dewrinkling process is utilized to give the garment a quality appearance. Then the dewrinkled garment is heat treated at a suicient temperature for an extended period of time to cure or set the thermosetting resin.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic ow diagram illustrating alternative techniques for manufacturing permanent press garments using the dewrinkling process of the invention.

FIG. 2 is a schematic flow diagram showing alternative techniques for dewrinkling initially dry garments either by laundering the garments, directly dewrinkling the dry garments, or dry cleaning and dewrinkling the garments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A suitable apparatus for carrying out the process is one basically identical to the apparatus shown in the aforementioned Wood U.S. Pat. 2,911,729. In general, this equipment includes a presteaming chamber and a heat treating chamber, the latter having means for supplying a downwardly directed stream of relatively low velocity air. To utilize this apparatus for carrying out the process of this invention the heat treating chamber is modified by installation of high temperature heating elements sufficient to increase the temperature in the heat treatment chamber to about 325 to 400 F. In addition, the means for supplying the downwardly directed stream of air are enlarged to supply a high velocity stream of at least about 1400 feet per minute. As such equipment modifications can be readily effected Within the skill of the art.

In carrying out the processes of the instant invention, a primary feature is that the garments are heat treated in the range of about 325 F. to 400 F. but for a period not to exceed the period which would substantially degrade the thermoplastic resin fabric constituent. Degradation of the fabric is defined as a softening and non-reversible change in form of the resin to the extent of adherence of filaments of the fabric together -or to the extent of substan-tial change in the surface texture thereof.

In the preferred form of the invention, a heat treatment period of about to 30 seconds is employed for dry garments and a period of about 1/2 minute to 11/2 minutes for moist garments. In operation of the processing equipment the period is kept to the minimum required for the heaviest or most moist garments to be treated so that all garments will be adequately dewrinkled. It is understood, of course, that a garment generally has three or more layers of fabric at the seams of the dewrinkling process and to be effective must be capable of substantially entirely removing the wrinkles from these several layers of fabric.

In the preferred embodiment, particularly when dewrinkling of so-called blend fabrics, consisting of a thermoplastic filament portion and a portion of wool, cotton or other natural fiber, initially dry garments are presteamed for a period of between 7.5-22.5 seconds, in the preferred embodiment. For moist garments the pref steaming may be eliminated or may be used to partially dry the moist garment to condition it for treating in the heat treatment section. It is known, of course, that steaming relaxes the natural fibers in the garment and thus greatly enhances the dewrinkling that occurs in the heat treating step. It has also been discovered, however, that steaming also enhances the dewrinkling of the thermoplastic fibers.

In the preferred form of the invention the garments are subjected to a downwardly directed stream of air, at a velocity of at least about 1400 feet per minute. Air velocities up to 2000 feet per minute have proven to be satisfactory for example. The high velocity air is passed over the garments while they are being heat treated and agitates the garments so that wrinkles present are shaken free as well as precluding new wrinkles from forming. It is also believed that the downward direction and the high velocity assist in drawing the fabric downwardly to pull the wrinkles out of the garment.

Typical examples of garments treated with the instant dewrinkling process are given below.

EXAMPLE I A heavy shop type jacket of 65% Dacron (TM)35% cotton, without permanent press, and containing at least a portion of a synthetic fabric was prestearned, then heat treated and agitated at a temperature of 360 F. for a period of 30 seconds on equipment of the type disclosed in Wood U.S. Pat. No 2,911,729, utilizing an air velocity of 500 feet per minute. The resulting condition of the garment, initially heavily wrinkled, was somewhat improved but was not acceptable in the trade as an unwrinkled garment.

Similar results were also obtained with a lightweight waitress uniform Iof 65 Dacron (TM)35% cotton blend fabric, processed in like manner.

EXAMPLE Il The processing equipment of Example I was modified to provide in its heat treatment chamber a variable temperature from 300 F. to 400 F. and a variable downward air jet velocity from 1400 feet per minute to 2000 feet per minute. This machine, through which hung garments are conveyed in side-by-side relationship, has a cabinet length of about 71/2 feet, some 3 feet of which comprises the steaming chamber and Vsome 4 feet of which comprises the heat treatment, air jet agitation chamber. The conveyor mechanism coursing these chambers is operable at a Variable speed, at from about units per hour through 500 units per hour. At these throughput rates, the time of occupancy of each garment in the heat treating chamber is about 66 seconds at the 100 units per hour rate and about 13.2 seconds at the 500 units per hour rate. For simplicity, in this and the following examples, the time of occupancy in the heat treatment chamber will be indicated simply as a matter of seconds.

A dry mans industrial shirt of medium weight, fabricated of 65% Dacron and 35% cotton, was conveyed through the processing equipment on a hanger at a speed to provide a time of occupancy in the heat treatment chamber of about 30 seconds, the air jet velocity being regulated to provide a velocity of about 1400 feet per minute, and the temperature in the heat treatment chamber being regulated to be 360 F. This garment, initially heavily wrinkled, came out of the heat treatment chamber essentially wrinkle free with only a slight mottling in appearance, which mottling appearance essentially disappeared after the hung garment was maintained at ambient temperature for about an hour.

Like processing of other weights of garments, including a heavy type shop jacket of 65% Dacron-35% cotton fabric constituency, and with permanent press characteristics produced like, highly satisfactory, dewrinkling. Similar results were also obtained with relatively light weight nylon waitress uniform garments.

The dewrinkling process as described above also is effectively utilized for removing Wrinkles from freshly laundered garments. Basically in these processes the garments typically are laundered at a temperature of about 160 to 190 F. followed by a gradual cooling of about 6 minutes. The gradual cooling is important to prevent what arecalled shock wrinkles, a condition exhibited by synthetic fibers in which the fiber retains any angular deformation existing at the time its temperature is lowered quickly from a laundering temperature of about 160-190 F. The garments are then normally spun dry for a period of about 3 to 5 minutes. At this point the garments may be subjected directly to the above pre-- ferred dewrinkling process by being steam treated and then heat treated in the presence of high velocity air or, as an alternative, may be further preconditioned by drying at a temperature of about F.l for 6 minutes and then gradually cooled for over 3 minutes prior to being subjected to the dewrinkling process.

An example of a freshly laundered dewrinkling process is given below.

EXAMPLE III A nylon uniform shirt of medium weight garment, originally soiled, and dry was laundered at a temperature of about F., then gradually cooled for about 10 minutes, then spun dry for about 5 minutes. One garment was then steam treated for a period of 25 seconds followed by a heat treatment at a temperature of 380 F. for a period of 60 seconds in the presence of a downwardly directed stream of air at a velocity of approximately 1800 feet per minute. The garment was of a high quality, dewrinkled appearance.

Another freshly laundered and spin dried garment, in this instance a triacetate-Dacron blend nurses uniform, was cooled then steam treated for a period of 50 seconds and followed by heat treating at a temperature of 325 F. for a period of 11/2 minutes in the presence of a downwardly directed stream of air at a velocity of about 1400 feet per minute. The resulting appearance of the garment was of a high quality suitable for acceptance in the trade.

Another process found to be of a great advantage using the above preferred dewrinkling process is in the manufacture of permanent press type garments. In these manufacturing processes the garment is either made from a fabric that has been treated with an uncured thermosetting resin or the garment is treated with the thermosetting resin after being made. During the cutting and sewing procedure necessary to make the garment, it becomes quite wrinkled. These wrinkles are removed using the above dewrinkling process by steam treating followed by heat treating above the softening temperature of the thermoplastic resin but for a time insufficient to actually degrade the resin. The agitated heat treatment takes place in like manner as in the earlier examples, and produces a high quality, dewrinkled condition following 4which the dewrinkled garments finally are heat treated for an extended period of time, suitably at a temperature of 300 F. for example, to cure the thermosetting resin. The final garment is wrinkle free and will exhibit the customary permanent press memory to resist wrinkling during further use.

As a practical matter a dewrinkling processing equipment must be operated at a selected temperature and a selected conveying speed which amounts to an approximation or an average of the temperatures and treatment times optimally desirable for each garment fed through the equipment during a given run, it being common practice of course to run a variety of more or less similar garments during a given run. Because of wide variances as to the nature of the one or more thermoplastic resins making up part or all of the fabric of various garments, and also by reason of considerable variety as to the specific nature of the thermosetting resin providing permanent press characteristics to garments of this type, it will 'be understood that certain types of garments, characterized by the presence of a thermoplastic resin having a relatively low or a relatively high softening temperature, will make desirable relatively fast or slow heat treatment times and relatively low or high heat treatment temperatures. Nonetheless, from a knowledge of the softening temperature of a given thermoplastic resin constituent, a temperature somewhat above such softening ternperature can be selected as the heat treatment temperature, and trial and error can readily determine a safe treatment time related to such relatively high heat treatment temperature, in any given instance. Accordingly, it is to be recognized that, with suitable selection of temperature of heat treatment and time of heat treatment, the invention is applicable to a wide variety of thermoplastic resin fabrics or resin containing fabrics. Thus, simply by way of typical example, it is known that certain cellulosic type fibers have known softening temperatures, e.g. acetate softens at about 400 F., rayon tends to decompose at temperatures above about 350 F., triacetate after heat treatment can tolerate temperatures up to about 450 F. before becoming sticky. Correspondingly, polymer fibers of the acrylic type develop stickiness beginning around 450 F., nylons are variable as to a stickiness temperature but are generally categorized in the 400 F.-450 F. in this respect, oleins in common usage develop melting tendencies above about 325 F., polyesters developed melting tendencies above about 480 F., and saran filament softens at temperatures as low as 240 F. From these considerations the selected temperature range of about 325 F. to about 400 F., as presented by the above discussion of the nature of the present invention, represents an averaging or approximation of the temperature range and correlative, relatively brief heat treatment time, considered to be acceptable and practical for most commercial dewrinkling operations, although in certain instances certain garments will be encountered which have a resin constituency requiring a relatively lower heat treatment temperature, or permitting a relatively higher temperature of heat treatment.

Accordingly, rather than limiting the general nature of the invention to any specific temperature range or time of treatment in the heat treatment phase thereof, the important and functionally effective consideration is.considered to be that a temperature slightly above the softening temperature of the thermoplastic resin constituent is most effective and is safe provided the heat treatment is limited to a short exposure time.

The relatively high heat treatment temperature and short exposure time affords a considerable commercial advantage from the point of view of not only good dewrinkling of the garments, but also from the point of view high throughput rates, the production rate capabilities of the present invention being much higher than prior practice involving temperatures below the softening ternperature of the thermoplastic resin fabric.

A further important feature of the invention, from the point of view of its commercial practicality, is that, although some degree of mottling or roughness may still persist in the garment as it comes out of the relatively high temperature heat treatment, the continued exposure of the garment to ambient moisture and temperature conditions causes what may be termed a tempering of the heat treated garment with some pick-up of atmospheric moisture and with gradual cooling, with progressive improvement of garment appearance and feel over a period of an hour or two after heat treatment, to the point the garment becomes quite wrinkle free. The relatively prolonged tempering period is, however, of no commercial consequence in that the leaving of the hung garments exposed to atmospheric moisture and temperature conditions is the normal way in which garments are handled after a dewrinkling treatment.

As shown by the drawing, a sizing substance may be added to a garment at the steaming station. Such sizing substance may be added to the water before it is converted to steam. The sizing would enter the garment in a vaporrfnls form and would thoroughly impregnate the cloth ers. From the foregoing, various further adaptations and variations of the processing techniques and system characterizing the present invention, will be apparent to those skilled in the art to which the invention is addressed, within the scope of the following claims.

What is claimed is: 1. A process of dewrinkling garments at least partly fabricated of a fabric comprising thermoplastic resin fabric, said process comprising:

hanging the garment, heating the hung garment above the softening temperature of the resin fabric for a period less than the time required to substantially degrade the resin fabric,

agitating the garment by downwardly directing a high velocity air stream over said garment while the garment is thus heated, and

gradually cooling the hung garment.

2. The process of claim 1, wherein the fabric is of a type impregnated with a thermosetting resin to impart permanent press characteristics thereto.

3. The process of claim 1, further including the step of steaming the garments prior to heating.

4. The process of claim 2, further including the step of steaming the garments prior to heating.

5. The process of claim 3, wherein said heating step includes heating the moist garment at a temperature in the range between about 325 -400 F. for less than about 1%; minutes.

6. The process of claim 5, wherein the garment is heated under agitation for a period of about 30-60 seconds.

7. The process of claim 1, wherein said heating step includes heating at a temperature in the range between about 325 400 F. for less than about 30 seconds.

8. The process of claim 7, wherein the garments are air dried prior to being treated and wherein said heating step includes heating for a period between about 5-10 seconds.

9. The process of claim 1, further comprising the step of slowly cooling the heated garment in the presence of ambient air for at least about 1 hour.

10. The process of claim 1, wherein the high velocit] air stream has a velocity of at least about 1400 feet per minute.

11. The process of claim 5, wherein the high velocity air stream has a velocity of at least about 1400 feet per minute.

12. The process of claim 8, wherein the high velocity air stream has a velocity of at least about 1400 feet per minute.

13. The process of claim 9, comprising steaming the garment prior to heating and agitation thereof, and heating the garment to a temperature in the range between about 325-400 F. while agitating the garment by an air stream having a downward velocity over the hung garment of at least about 1400 feet per minute.

14. A process of dewrinkling a laundered garment containing a fabric at least a portion of which is thermoplastic resin, comprising:

laundering the garment at a temperature of from about 135190 F.; preconditioning the garment by:

gradually cooling the laundered garment, and spin drying the cooled garment;

dewrinkling the spun dried garment by:

hanging the laundered and preconditioned garment;

steam treating the hung garment; and

heat treating the hung garment at a temperature above the softening temperature of the thermoplastic resin for a time less than the time required to substantially degrade the resin fabric; and

gradually cooling the garment.

1S. The process of claim 14, further including the preconditioning steps of:

drying the spun dried garment at a temperature of about 130 F. for about 6 minutes, and

gradually cooling the garment for at least about 3 minutes.

16. The process of manufacturing an unwrinkled garment containing a fabric at least a portion of which is thermoplastic resin and containing a thermosetting resin to impart permanent press characteristics to the garment, comprising:

fabricating the garment of a fabric at least a portion of which is thermoplastic resin;

applying to the fabric the thermosetting resin in uncured form;

dewrinkling the garment after the resin is applied by:

hanging the garment; steaming the hung garment; and heat treating the hung garment at a temperature above the softening temperature of the thermoplastic resin for a period less than the time necessary to substantially degrade the thermoplastic resin while agitating the hung garment by a downwardly directed jet of air at a velocity of at least about 1400 feet per minute; thereafter curing the thermosetting resin to impart permanent press characteristics thereto; and gradually cooling the garment.

17. The system of claim 16, comprising applying the thermosetting resin after the garment is made.

18. The system of claim 16, comprising applying the thermosetting resin before the garment is made.

References Cited UNITED STATES PATENTS 2,734,830 2/1956 Hagge et al 117-139.5X 2,950,553 8/1960 Hurwitz 117-139.4X 3,424,545 1/ 1969 Bauman 8-137 WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner v Us. c1. XR. 117-66, 119.8, 138.6, 139.4; 6 137, 149.1; 34-31, 37

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,576,661 Dated April 27, l97l Inventor(g) JOHN W. DEKOEKKOEK It is certified that error appears in the above-identified patent; and that said Letters Patent are hereby corrected as shown below:

In the heading of the drawing sheet change "DEKOEKKOER" to "DEKOEKKOEK" Column l, at line 69, change "has" to have Column 2 at line l5 cancel "of" at lines l5 and l6 chang "a portion" to in part --5 at lines 30 and 3l, change "quickly produce" to the quick production of Column 3 at line 7 change "As such" to Such at lines 31+ and 35, cancel in the preferred embodiment".

Column 1+, at line Hl, change "of" to for --5 at line 6D, cancel "garment", at line 63, change nOne" to The Column 5, at line 57, after the comma insert and --5 at line 63 after "LISOOP" insert range --5 at line 7l, change "and correlative," to correlative with the at line 72, cancel the comma.

Column 8, at lines 2M and 26, change "system" to process Signed and sealed this 3rd day of April 1973.

[SEAL] Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

